Windows Virtual PC provides the capability to run multiple Windows environments such as Windows XP Mode from your Windows 7 desktop. For information on how to set up Windows Virtual PC and Windows XP Mode, check out Running Windows Virtual PC with Windows XP Mode in the Documentation section.

More Info & Steps at;

http://www.microsoft.com/windows/virtual-pc/default.aspx
&
http://www.microsoft.com/windows/virtual-pc/download.aspx
&
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=0e8fa9b3-c236-4b77-be26-173f032f5159